The present invention relates to a color image recording apparatus for recording a colored image on a photosensitive recording medium.
One conventional method for recording a colored image on a color photosensitive recording medium (hereinafter also referred to as "photosensitive sheet") employs color separation filters of red (R), green (G) and blue (B) for producing color-separated mask members from an original color image. The photosensitive sheet is exposed to light successively through these mask members. There is also known a process for applying white light directly to a colored original image and exposing a photosensitive sheet to light reflected by the colored original image. The former colored image recording method is more efficient than the latter process in that the intensity of exposure energy required to be applied to the photosensitive recording medium by the former method is much smaller than that required by the latter process.
One inhouse proposal has been made with respect to a color image recording apparatus for electrophotographically producing mask members using toner as a light-shielding substance on a light transmissive sheet, and exposing a photosensitive sheet to light through such mask members for reproducing a colored image on the photosensitive sheet.
Further, subsequent inhouse proposal has been made as described in a copending U.S. Pat. Application Ser. No. 184,576 filed on Apr. 21, 1988 regarding a color image recording apparatus for producing mask members using a commercially available monochoromatic printer such as a laser beam printer, and reproducing a colored image in the same manner as disclosed in the above proposal. In the recording apparatus disclosed in the copending application, the mask members of red (R), green (G) and blue (B) are printed on ordinary paper sheets of cut form by the monochromatic printer, and monochromatic lights of red (R). green (G) and blue (B) are applied successively to a photosensitive recording medium through the mask members. Since the mask members are produced on the ordinary plane papers, maintenance and handling to the mask members are facilitated, and the mask members are convenient to use especially when a number of colored images are to be produced using the same mask members or a colored image is to be reproduced at a later time using the mask members.
There has been also another inhouse proposal regarding an image recording apparatus in which mask members produced on respective cut sheets have respective identification marks indicating the colors of the mask members. This apparatus has a sensor for reading the identification marks on the mask members that have been delivered to an exposure position, so that the colors of lights to be applied through the mask members to a photosensitive sheet can automatically be selected so as to correspond to the mask members in use. This apparatus allows the photosensitive sheet to be exposed to lights of desired colors irrespective of the sequence in which the mask members may be delivered to the exposure position. Therefore, the mask members may be manufactured in any desired order by a monochromatic printer, and the manufactured mask members may be inserted in any desired order into the color image recording apparatus, since a colored light corresponding to the applied mask member is irradiatable.
Further, in the copending U.S. Pat. Application Ser. No. 184,576, now U.S. Pat. No. 4,884,082 issued Nov. 28, 1989, which discloses the color image recording apparatus using the mask members, a mask member circulating passage is provided for repeatedly feeding the mask members to the exposure position and for positioning them when a number of colored images are to be reproduced from one set of such mask members. With the mask member circulating passage, it is not necessary to prepare mask members again on a monochromatic printer or to insert the mask members manually into a mask member feeder each time a colored image is to be reproduced. Consequently, color images can be recorded at a high speed.
The color image recording apparatus according to the subsequent inhouse proposal has three fluorescent lamps for emitting lights having wavelengths corresponding to red (R), green (G) and blue (B). However, these three fluorescent lamps and their respective starter circuits render an overall size and require large space, and make the color image recording apparatus expensive to manufacture.
To avoid this drawback, there has been know a process for using a light source for emitting white color light, producing lights of red, green end blue from the white color light using color separation filters of the corresponding colors, end exposing a photosensitive sheet to the color-separated lights.
With such arrangement and the color image recording apparatus disclosed in the copending U.S. application, it has to be determined which mask member has been delivered into the exposure unit, and then a desired one, which corresponds to the determined mask member, of the color separation filters must be brought into a position in the path of light from the light source. Therefore, it takes some time until the desired color separation filter is positioned in place. If the mask members are inserted in a sequence different from the order in which the color separation filters are successively brought into the path of light from the light source, then the color separation filters must be switched around each time and exposure cycle is to be carried out, resulting in a time loss. Such a time loss is increased especially when a number of colored images should be produced using one set of mask members.